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INTRODUCTION
This chapter describes the fuel system for the Global Express aircraft.
Fuel is contained in a wet wing box structure, which is sealed to form the three main
separate wing tanks, and a smaller quantity of fuel is carried in a separate aft fuselage
tank. The tanks are vented to atmosphere and slightly pressurized by an air scoop
located on the lower surface of each wing. A scavenge pump purges fuel from the vent
lines and a climb vent, located in each main wing tank, provides ventilation when the
airplane is in a nose up attitude.
Each engine is supplied with fuel from its respective feed tank which contains two
alternating current or AC primary pumps, and one Direct Current (DC) backup (or
Aux) electrical boost pump. The transfer system maintains the feed tanks full during
all attitudes, and provides automatic transfer of fuel from the center tank and aft tankto the main wing tanks.
Lateral balance between left and right main tanks is controlled automatically by the
Fuel Management and Quantity Gauging Computer (FMQGC), or manually through
switch selections in the flight compartment.
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Flight deck control is provided on the overhead panel, and fuel quantity and warnings
are displayed on EICAS.
A single point pressure refuel/defuel adapter is provided which is connected to a
manifold containing shutoff valves. Pressure refueling can be done either
automatically or manually. Gravity filling is provided for each wing tank and for the
center tank.
A dual channel FMQGC continuously monitors the following:
Fuel quantity indicating
Left, right engine and APU feed
Wing to wing balance (wing XFER)
Center tank transfer
Aft tank fuel transfer
Refuel/Defuel
GX
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_001
Main Wing Tank
Engine DrivenPumps
AC Motor Pumps(transfer)
*
Feed Tanks
DC Pumps(start, emergencyand wing transfer)
AC Motor Pumps(transfer)
AC Motor Pumps(engine feed)
Center Tank AFT Tank*
Note*Not on Global 5000
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Any fault detected by the fuel system computer is annunciated on Engine Indication
and Crew Alerting System (EICAS) in the form of a visual and/or aural alert, and/ormaintenance diagnostics.
FUEL TANKS
All fuel is carried in three integral tanks (left wing, right wing and center wing) and a
smaller aft fuselage tank (contained in a structurally enclosed bladder).
The inboard section of each wing is designated as a feed tank, from which each engine
draws its fuel. Fuel flows from the outboard sections of each wing tank, into the feed
tank (by gravity), through swing check valves in the baffles of each main tank. The
check valves allow fuel flow in the inboard direction only. This will restrict large fuel
movements, and limit center of gravity shifts in airplane changes of attitude. Fuel isalso transferred into the feed tanks, from the center fuselage and aft fuselage tanks by
the transfer system.
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DESCRIPTION
FUEL SPECIFICATIONS
For information on fuel additives, temperature limitations and approved fuels, refer to
AFM - LIMITATIONS Chapter 2.
Fuel remaining in a tank when the appropriate fuel quantity indicator reads zero is not
usable. Based upon a fuel density of 6.75 lb/U.S. gallon, the maximum usable fuel
load for each fuel tank is given below:
PRESSURE REFUEL (+0 / -1%)
Tank Volume Fuel Mass
Left main tank 8,435 liters 2,229 U.S. gal 6,825 kg 15,050 lb
Right main tank 8,435 liters 2,229 U.S. gal 6,825 kg 15,050 lb
Center tank 6,265 liters 1,655 U.S. gal 5,075 kg 11,150 lb
Aft tank 1,275 liters 337 U.S. gal 1,025 kg 2,300 lb
Total 24,410 liters 6,450 U.S. gal 19,750 kg 43,550 lb
based on a fuel density of 0.809 kg/liter (6.75 lb/U.S. gal), rounded to the nearest 25 kg or 50 lb. Fuel Mass is
provided for reference only and should not be considered limiting.
GRAVITY REFUEL (AIRPLANE LEVEL)
Tank Volume Fuel Mass
Left main tank 7,760 liters 2,050 U.S. gal 6,275 kg 13,850 lb
Right main tank 7,760 liters 2,050 U.S. gal 6,275 kg 13,850 lb
Center tank 6,245 liters 1,650 U.S. gal 5,050 kg 11,150 lb
Aft tank not available not available not available not available
Total 21,765 liters 5,750 U.S. gal 17,600 kg 38,850 lb
based on a fuel density of 0.809 kg/liter (6.75 lb/U.S. gal), rounded to the nearest 25 kg or 50 lb. Fuel Mass is
provided for reference only and should not be considered limiting.
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FUEL AND WATER DRAINS
All tanks have flush self-closing water drain valves, installed at various low points, to
permit draining of any accumulated water or residual fuel. They are located at the low
point of each wing. Three gravity fill caps are provided for wing and center tank
gravity refueling.
Center Fuel TankWater Drains
Aft Fuel Tank Fueland Water Drain
Gravity Fuel Fill
Wing Fuel Tankand Water Drain
Center WingGravity Fuel Fill
Wing Fuel Tankand Water Drain
Wing Fuel TankGravity Fuel Fill
GX
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_002
LEGEND
UPPER SURFACE
LOWER SURFACE
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AC BOOST PUMPS
Two AC boost pumps, also referred to as primary boost pumps, are located in each
feed tank. They normally supply fuel to the engines in all airplane ground and flight
mode operations. Each pump is capable of maintaining an engine (fuel demand) in all
modes of engine operation. The two pumps are continuously on, whenever the engine
is operating and AC power is available. Both boost pumps (two on each side) may be
inhibited by selection of one of the individual switches on the fuel control panel. The
boost pumps are controlled automatically through the Alternating Current Power
Center (ACPC), when a fuel command is received.
DC AUXILIARY PUMPS
DC powered auxiliary pumps (AUX pumps) one in each feed tank, are used for thefollowing:
APU starting
Wing to wing transferring of fuel
Engine feed in the event of an AC boost pump failure
During takeoff and landing with at least one of the following:
Flaps > 0, landing gear down and in flight, or low wing fuel condition (600
pounds each wing)
Each AUX pump may be inhibited by selecting off a switch on the fuel control panel.
The pumps are automatically controlled by the Secondary Power Distribution
Assembly (SPDA).
NOTE
When an AUX pump is used for wing transfer mode of operationand an AC pump fails, priority is given to the engine feed systemand the automatic wing transfer operation will be inhibited.Manual override of the automatic selection is possible via thefuel control panel.
CENTER TRANSFER PUMPS
Two center transfer pumps (controlled by the FMQGC) are used to transfer fuel fromthe center tank to the main wing tanks. There is no manual selection available to
transfer fuel from the center tank to the wings.
AFT TRANSFER PUMPS
Two aft transfer pumps and associated shutoff valves are used to transfer fuel from the
aft fuel tank to the wing tanks. Transfer is scheduled by the fuel computer or by a
switch selection on the fuel control panel.
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VENT SYSTEM
An open vent (no float valves or flame arrestors) system is used to control the pressure
in the fuel tanks. It consists of vent line tubing and ram air inlet/outlet scoops, to
ensure adequate venting of all fuel tanks. The vent lines connect the two air scoops to
the fuel tanks, and the fuel tanks to each other. The lines are drained of fuel which is
returned to the feed tanks during operation. The low point of the main vent line is
continuously scavenged by a jet pump.
The vent line distribution is to a high point in the fuselage, preventing fuel from
reaching either of the two ram outlets and spilling overboard. If any fuel passes the
high point, it is collected by the surge box and is drained back to the tank before it
reaches the outlet. Each surge box vent line tubing runs vertically along the fuselage
side wall, and is coupled to the wing, center and aft tanks.The vent system is fully redundant, such that any single blockage does not affect the
venting capability.
VENT SYSTEM SCHEMATIC
LEFT WING TANK
CENTERWINGTANK
AIRSCOOP
AIRSCOOP
RIGHT WING TANK
AFTTANK
GX
_11
_003
RIGHTSURGE
BOX
LEFTSURGE
BOX
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PRESSURE RELIEF VALVES
Relief valves are used to protect the tanks from over pressurization, in the case of
failure of the vent system and/or refuel shutoff valve. They are located in the wing,
center and aft tanks. The aft tank relief valve has a similar function as the center and
wing tank relief system, but also incorporates a negative-pressure relief feature which
can activate in an emergency descent.
FUEL MANAGEMENT QUANTITY GAUGING COMPUTER (FMQGC)
The FMQGC consists of a dual channel computer with BITE, utilizing capacitance
type probes in each tank to continuously measure the quantity of usable fuel. The fuel
computer performs all digital processing related to the system control and indication
and performs computations associated with fuel gauging system requirements. Thefollowing schematic represents inputs and outputs of various components and systems
operations.
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FMQGC SCHEMATIC
ENGINE INDICATING AND CREW ALERTING SYSTEM ANDCENTRAL AIRCRAFT INFORMATION MANAGEMENT SYSTEM
FUEL SYSTEMCOMPONENTS
Boost Pumps INHIBWing Transfer ModeAft Transfer Mode
XFEED Mode
Fire HandlesAPU On
L Engine OnR Engine On
Fuel QuantitiesFuel Temperature
EICAS MessagesCautionAdvisory
StatusEICAS Inputs from
other sourcesDisplays Data:
Total Fuel QuantityIndividual Tank Quantities
Preselect QuantityAlert Messages
PUMP PRESSURE SWITCHESSOVS POSITION FEEDBACK
COCKPITCONTROL
PANEL
COCKPIT FUELPANEL
CHANNEL
1
CHANNEL
2
FMQGC
SENSOR DATA:TANK PROBES
COMPENSATORSDENSITOMETERTEMPERATURE
HI/LO LEVEL
CENTER WINGTANK
AFT TANK Legend
Input and output
Input or output
RIGHT WING TANKLEFT WING TANK
GX
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_004
REFUEL/DEFUELPANEL
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FUEL CONTROL PANEL
The fuel control panel is located on the overhead panel in the flight compartment. The
fuel control panel defines the operational modes, component controls, and component
inhibits.
The fuel control panel has switches, which when selected, override the automatic
control of certain components within the fuel system. Switch selections from this
panel are sent to the ACPC. The ACPC will then control the system from the inputs
received from the panel. The switch lamps come on when selected in combination
with certain EICAS messages, which represent the panel configuration or failure
within a given system.
FUEL CONTROL PANEL
FUELR
WING FEED
INHIBIT
L
WINGFEED
INHIBIT
XFEED SOV
FAIL
OPEN
AUXPUMP
OFF
PRIPUMPS
OFF
L RECIRC
ON
AUX PUMP
OFF
PRIPUMPS
OFF
R RECIRC
ON
AFT XFER
AUTO
OFF ON
OFF
AUTO
WINGXFER
WING XFER SwitchAUTO
OFF
selection Provides a means of transferring fuel from onewing to the other. Controlled by the FMQGC. or selection A left to right, or a right to left selection,provides a means of tranferring fuel (in the direction of the arrow) fromone wing tank to the other. selection Provides a method of inhibiting wing to wing transfer.
XFEED SOV SwitchFAIL
OPEN
l ight Will come onwhen the valve does notgo to the commandedposition.
light When theswitch is selected, thecrossfeed valve opens andinterconnects the enginefeed lines.
AUX PUMP SwitchOFF light Indicates that
the right auxiliary pump hasbeen disarmed. The leftAUX PUMP has similarlogic.
PRI PUMPS SwitchOFF light Indicates that
both left wing primarypumps have beendisarmed. The right PRIPUMPS switch has similarlogic.
GX
_11
_005
AFT XFER SwitchAUTO
ON
OFF
selection Provides a means of transferringfuel from the aft tank to the wing tank. Controlled by
the FMQGC. selection Provides a manual method ofcontrolling the transfer schedule. selection Inhibits the forward transfer of fuel.
RECIRC Switch(If installed)
ON light Indicates thatthe FRTT valve is openwhen commanded by flightcrew.
R RECIRC
INHIBIT
OFF
RECIRC Switch (If installed)OFF light On AC equipped
with -9 FMQGC or later. Recirc
is an automatic ON feature andthe switches are used to inhibitthe system if required. The LeftRecirc Inhibit has a similar logic.
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FUEL SYSTEM SYNOPTIC PAGE
The FUEL synoptic page provides an overview of system status, as represented below
with both left and right engines running and no transferring of fuel taking place.
FUEL SYNOPTIC PAGE
NOTE
For the remainder of this chapter, the synoptic page withrecirculation shown will be used as a default.
FUEL
AUX
O
C
APU
O
C
TOTAL FUELOTAL FUEL
4355OLBS
5O5OLBS
AUX
LBS 5O
5O5OLBS
FUEL USEDU EL U SE D
OLBS
LO PRESSO P RE SS
3
C
3OO
LBS
3
C
LO PRESSO P RE SS
FUEL
AUX
C
APU
C
TOTAL FUELOTAL FUEL
4355OLBS
5O5OLBS
AUX
LBS 5O
5O5OLBS
FUEL USEDU EL U SE D
OLBS
LO PRESSO P RE SS
3
C
3OO
LBS
3
C
LO PRESSO P RE SS
DC Auxiliary Pump
ACBoost
Pumps
AftTransfer
Pump
CenteTransferPump
r
GX
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_006
Without Fuel Recirculation With Fuel Recirculation
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EICAS PHILOSOPHY
The following represents the EICAS symbols and flow line logic for the fuel synoptic
page. The symbols are shown in serviceable and failure conditions.
VALVE AND FLOW LINE LOGIC
PUMP AND FLOW LINE LOGIC
DIRECTION OF FLOW
DIRECTION OF FLOW
VALVENOT FAILED
OPEN
CLOSED
TRANSIT
OFF
PUMPFAILEDON
INVALID
ON
PUMPFAILEDOFF
INVALID
VALVEFAILED
P
P
P
P
P
GX
_11
_007
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FUEL SHUTOFF VALVE DISPLAYS
FUEL
AUX
3
C
APU
3
C
TOTAL FUELOTAL FUEL
O6OOLBS
48OO
LBS
AUX
LBS
4OOO
LBS
FUEL USEDUEL USED
3 OOOLBS
LO PRESSO PRESS
3
C
8OO
LBS
3
C
LO PRESSO PRESS
WING Transfer SOVControlled by the FMQGC or theWING XFER switch on the fuelcontrol panel.
Engine FeedShutoff Valve
.NOTE
Applicable engine FIREDISCH handle
: The engine runswitches activate theHPSOV located in theFMU not these shut-offvalves. These are onlyactivated by the FIREDISCH handle.
Fuel Crossfeed SOVControlled by theswitch on the FuelControl Panel. It isused to interconnectthe engine feed lines.
AFT Tank Transfer ValveControlled by the FMQGCor the AFT XFER switchon the fuel control panel.
APU Feed Shutoff Valve Activated by the RUNposition switch on theAPU control panel. Also controlled by theAPU FIRE DISCHhandle.
GX
_11
_008
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FUEL FILTER, QUANTITY AND TEMPERATURE READOUT
FUEL
AUX
3
C
APU
3
C
TOTAL FUELOTAL FUEL
43 OOLBS
49OOLBS
AUX
LBSOOO
49OO
LBS
FUEL USEDUE L U SED
OOLBS
LO PRESSO PRESS
3
C
OOLBS
3
C
LO PRESSO PRESS
Wing Fuel QuantityIndicates fuel quantity, in therespective wing tank, inpounds (lbs).
Total Fuel QuantityIndicates fuel quantity, in all
fuel tanks, in pounds (lbs).
Fuel Used Quantity ReadoutIndicates fuel quantity burned.
Fuel Quantity Readout(Aft Tank)Indicates fuel quantity in theaft tank, in pounds (lbs).
Fuel Quantity Readout(Center Fuselage Tank)
Indicates fuel quantity, in thecenter tank, in pounds (lbs).
Engine Inlet FuelTemperature Green
Amber
Engine fueltemperature is 5C.
Engine fueltemperature is < 5C.
>
Fuel Filter Flow LineGreen
Amber
Indicates normalfuel flow to the engine. Fuel pressuredrop exists across the filter,flow line from the filter tothe engine turns amber.
GX
_11
_009
Bulk Fuel TemperatureReadoutPrior to -9 FMQGC Green
Amber
Fuel Recirculationsystem is ON: Green
Amber
Temperature offuel in tanks is between-35C and +43C.
Temperatureof fuel in tanks is lower
than -35C or greaterthan +43C.
Temperature offuel in tanks is between-35C and 0C.
Temperatureof fuel in tanks is lowerthan -35C or greaterthan 0C.
Bulk Fuel TemperatureReadout-9 FMQGC or later Green
Amber
Fuel Recirculationsystem is ON: Green
Amber
Temperature offuel in tanks is between-35C and +54C.
Temperatureof fuel in tanks is lower
than -35C or greaterthan +54C.
Temperature offuel in tanks is between-35C and 10C.
Temperatureof fuel in tanks is lowerthan -35C or greaterthan 10C.
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FUEL PUMP DISPLAYS
FUEL
AUX
3
C
APU
3
C
TOTAL FUELOTAL FUEL
37OOOLBS
36OOLBS
AUX
LBS
OOO
3 OOLBS
FUEL USEDUE L U SED
56OOLBS
LO PRESSO PRESS
3
C
OOLBS
3
C
LO PRESSO PRESS
FUEL
AUX
3
C
APU
3
C
TOTAL FUELOTAL FUEL
37OOOLBS
36OOLBS
AUX
LBSOOO
3 OOLBS
FUEL USEDUEL US ED
56OOLBS
LO PRESSO PRESS
3
C
OO
LBS
3
C
LO PRESSO PRESS
L or R DC Auxiliary PumpsON
NOTE
OFF
For takeoff and landing, primary pumpfailure, and wing transfer of fuel.
: The AUX PUMP cannot be used to supportthe engine feed system and wing transfer at thesame time. In auto, engine feed will have priorityover wing transfer. Manual overide is alwayspossible.
When commanded by the switch on theFuel Control Panel. When both primary pumps are on and no wingtransfer is required.
Center Transfer PumpsControlled by the FMQGC andtransfers center tank fuel to thewing tanks. No manual control.
L or R AC Boost PumpsON
OFF
At all times with the enginesrunning. When commanded by theswitch on the Fuel Control Panel.
AFT Transfer PumpsON
OFF
When requested by thecomputer or selected on the FuelControl Panel. When commanded by theswitch on the Fuel Control Panel. When commanded by the FMQGCin AUTO mode.
GX
_11
_010
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FUEL QUANTITY AND INDICATION
The fuel quantity gauging system is an ac-type capacitance system. Fuel quantity
probes, compensators, densitometers, temperature sensors and high level detectors are
inputs received by the FMQGC. The FMQGC uses this acquired data to compute the
fuel quantity for each tank and total fuel quantity remaining on board the airplane.
The FMQGC outputs the computed individual fuel tank, total quantity and fuel
temperature for EICAS display. The fuel system computer corrects for airplane pitch
attitude and presents the corrected information of individual tank quantities, and total
fuel quantity displayed on EICAS. The FMQGC can display quantity in either pounds
(standard) or kilograms (optional). The primary EICAS page displays fuel quantity in
all fuel tanks, and total fuel in the airplane.
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FLIGHT MANAGEMENT DISPLAY
When both engines are started, the Flight Management System (FMS) fuel quantity
switches from Fuel Quantity Gauge System (FMQGC) to FMS computed fuel
quantity, based on fuel flow data from the engines and APU.
Fuel quantity information to the FMS is used for monitoring and sensing, to assist in
determining a fuel leak. When a fuel leak is detected, a crew alert (MSG on the
Primary Flight Display) will be displayed and a message will appear on the scratchpad
of the FMS CDU.
COMPARE FUEL QUANTITY0DEPARTURE
0PERFORMANCE INITLB 5/50BOW
51000PASS/@ LB0
5/170
0F UE L ( GA UG E) P AS S W T00
25000 23900( ) 8500
0CARGO GROSS WT00
200 770500
CONFIRM INIT0
COMPARE FUEL QUANTITY0DEPARTURE T.O.INIT0
000ACTIVE FLT PLAN 1/40BOW PASS/@ LB0
0/170
0 00055 154NM
15820 (00+21
00000001152ZKPHX
SJN
0 00059 121NM
15820 (00+15 .75M/10000A
CLS
ABQ
0ORIGIN
.75M/10000A
CLSCOMPARE FUELQUANTITYDisplays whenthe gauge fuelweight and theFMS fuel weightdiffer by morethan 2% of theBasic OperatingWeight (BOW).
GX
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_012
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ENGINE FEED SYSTEM
Fuel is provided to each engine from the two AC boost pumps. In normal operation,
both boost pumps are continuously on, and provide all engine fuel flow once the
engine is started. The AC pumps are located in the inboard section of each wing (feed
tank), and each AC pump is powered by a separate bus.
Loss of pressure at any AC boost pump causes the DC pump to come on, to provide a
back up of the remaining boost pump. The DC pumps also come on automatically for
takeoff, based on flaps/slats position and weight on wheels logic.
The engine fuel burn schedule is automatically controlled by the FMQGC to ensure
correct distribution for all airplane configurations.
The engine fuel burn sequence is as follows: Fuel from the wing tank will burn first
When the wing tanks get below 93%, fuel transfers from the center tank to the
wing tank until it is at or above 97%
When the center tank empties, fuel from the wing tanks continue to burn
When either wing tank reaches 5,500 pounds, fuel transfers from the aft tank
Once the aft tank is empty, the wing tanks will continue to burn the remaining fuel
Airplanes which do not incorporate fuel recirculation.The engine fuel burn sequence is as follows:
Fuel from the wing tanks will burn first
When the wing tanks get below 93%, fuel transfers from the center tank to the
wing tank until it is at or above 97%
When the center tank empties, wing tank continue to burn
When either wing tank reaches 4,000 pounds, fuel transfers from the aft tank
Once the aft tank is empty, the wing tanks will continue to burn the remaining
fuel
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Engine Feed System Indication
The left FUEL synoptic page below represents the normal engine start mode of
operation. The right engine is started using the Auxiliary Power Unit (APU) as the
source of electrical power and left engine is off. The right Fuel synoptic display
represents the right engine on speed.
The FUEL synoptic page below represents airplane configuration with the APU shut
down, both engines on, the AC pumps running, and the DC pumps on standby.
FUEL
AUX
3
C
APU
3
C
TOTAL FUELOTAL FUEL
384OOLBS
46OOLBS
AUX
LBSOO
46OOLBS
FUEL USEDU EL U SE D
3OOLBS
LO PRESSO P RE SS
3
C
OLBS
3
C
LO PRESSO P RE SS
FUEL
AUX
3
C
APU
3
C
TOTAL FUELOTAL FUEL
384OOLBS
46OOLBS
AUX
LBSOO
46OOLBS
FUEL USEDU EL U SE D
3OOLBS
LO PRESSO PRESS
3
C
OLBS
3
C
LO PRESSO PRE SS
GX
_11
_013
FUEL
AUX
3
C
APU
3
C
TOTAL FUELOTAL FUEL
384OOLBS
46OOLBS
AUX
LBSOO
46OOLBS
FUEL USEDU EL U SE D
3OOLBS
LO PRESSO P RE SS
3
C
OLBS
3
C
LO PRESSO P RE SS
GX
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_014
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TRANSFER SYSTEM
Fuel contained in the center tank and the aft fuselage tank cannot be fed directly to the
engine, but must be first delivered to the feed tanks by the transfer pumps. The normal
sequence of fuel usage is to transfer center tank fuel into the wings as required, to keep
the wings full during climb and cruise while holding the aft fuselage tank full.
After depletion of center tank fuel quantity, fuel continues to be burned from the wing
tanks until 5,500 lb. of fuel remains in either wing tank, at which point, transfer of fuel
from the aft tank to the feed tanks is initiated. The transfer from the aft tank is then
continuous until the aft tank is empty. When the aft fuselage tank fuel is depleted, no
further transfer of fuel is required, since all remaining fuel is contained in the wing
tanks.
Control of fuel transfer from the center and aft tanks is normally under control of the
fuel computer. Manual override is provided to command transfer of aft tank fuel into
the feed tanks via the fuel control panel. There is no manual override for the center
tank transfer system.
Airplanes which do not incorporate fuel recirculation.
The engine fuel burn sequence is as follows:
After depletion of center tank fuel quantity, fuel continues to be burned from the
wing tanks until 4,000 pounds of fuel remains in either wing tank, at which point,
transfer of fuel from the aft tank to the feed tanks is initiated. The transfer from
the aft tank is then continuous until the aft tank is empty. When the aft fuselage
tank fuel is depleted, no further transfer of fuel is required, since all remaining
fuel is contained in the wing tanks.
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CENTER TRANSFER
Fuel transfer from the center tank to wing tank is completely automatic through the
control of the FMQGC. The FMQGC monitors the fuel level and quantities in the
wing tank (using fuel probes, compensators, densitometers, and temperature sensors)
to control fuel transfer from the center tank to the wing tanks. Fuel will be transferred
from the center tank and delivered to the wing feed tanks, through the use of two
center transfer pumps.
The FMQGC will start the applicable center transfer pump(s) when each individual
wing tank reaches approximately 93% of its fuel tank capacity. The FMQGC will
automatically stop the center transfer pump(s) when the respective wing tank reaches
greater than 97%, of its fuel tank capacity.
The FUEL synoptic page represents the center tank transfer system in operation, with
both engines running.
WING TRANSFERThe wing transfer system permits fuel to be pumped from either side of the airplane to
the other, using the DC auxiliary pumps and motor operated shutoff valves.
The wing transfer system provides a means of correcting lateral fuel imbalance. It may
be used in automatic mode via FMQGC, or manual mode as selected by the cockpit
fuel control panel. Fuel imbalance at a predetermined value will be annunciated on the
EICAS display in the form of a caution message.
FUEL
AUX
3
C
APU
3
C
TOTAL FUELOTAL FUEL
37 OOLBS
35OOLBS
AUX
LBSOOO
35OOLBS
FUEL USEDU EL U SE D
5 OOLBS
LO PRESSO P RE SS
3
C
OOLBS
3
C
LO PRESSO P RE SS
Center TransferPumps
GX
_11
_015
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AUTO WING TRANSFER
The auto wing transfer mode is only enabled when the slat/flap handle is in the in/zero
position. In this mode, the FMQGC will correct lateral fuel imbalances of 400 pounds
on ground and in flight. The FMQGC will control and operate the DC auxiliary pumps
and wing transfer SOVs as necessary, to pump fuel from the feed tank into the
opposite wing. Once commanded on, the wing transfer system remains on until lateral
fuel imbalance is zero.
In the event of a center tank transfer pump failure, fuel will be transferred from the
operating center tank transfer pump to its respective wing tank. The automatic wing
transfer system will maintain lateral fuel balance, to ensure that fuel contained in the
center tank is available to both engines.
MANUAL WING TRANSFER
In manual mode, the wing transfer system is controlled using the fuel WING XFER
switch. Once selected, the wing fuel transfer continues until the WING XFER switch
is selected off on the fuel control panel.
The FUEL synoptic page represents the left to right wing transfer mode of operation
with both engines running.
FUEL
AUX
3
C
APU
3
C
TOTAL FUELOTAL FUEL
345O
LBS
585OLBS
AUX
LBS
54OOLBS
FUEL USEDU EL U SE D
9 OO
LBS
LO PRESSO P RE SS
3
COO
LBS
3
C
LO PRESSO P RE SSOFF
AUTO
WINGXFER
DC Auxiliary PumpIn wing transfer demand,
commanded on by the FMQGC.
Wing Transfer Shutoff ValveCommanded on by the FMQGCor manually by the switch on thefuel control panel.
GX
_11
_016
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CROSSFEED
The crossfeed system permits interconnection between the left and right engine feed
lines, using a shutoff valve. This will enable both engines to be fed by either feed tank,
or alternatively, enabling a single engine to be supplied from both feed tanks.
For normal airplane operations, the crossfeed shutoff valve is closed, isolating the feed
lines and ensuring that each engine is supplied fuel only from its own side of the
airplane. Opening the crossfeed shutoff valve interconnects the feed lines, enabling
fuel to flow from one engine feed line to the other.
No automatic means of controlling the crossfeed SOV is provided, and selection has to
be made using the XFEED SOV switch on the fuel control panel.
In single engine operating mode, with the crossfeed shutoff valve opened, fuel flowsfrom both feed tanks via the AC primary pumps to the single engine, and fuel flow
rates from both sides of the airplane are considered essentially the same. Therefore the
airplane can be flown indefinitely without developing any significant lateral fuel
imbalance.
The FUEL synoptic page below represents the fuel crossfeed mode of operation, with
the crossfeed shutoff valve selected open, left engine shut down, left engine feed
shutoff valve closed, and the right engine running.
A secondary use of the crossfeed system (as a back-up to the wing transfer system) is
to provide means of correcting lateral C of G imbalances, by temporarily inhibiting the
flow of fuel from the light side of the airplane. Fuel will then be supplied to both
engines from the heavy side until lateral fuel balance is within desired limits.
FUEL
AUX
3
C
APU
3
C
TOTAL FUELOTAL FUEL
34OOLBS
56OOLBS
AUX
LBS
56OOLBS
FUEL USEDU EL U SE D
86OO
LBS
LO PRESSO P RE SS
3
C
OOLBS
3
C
LO PRESSO PR ESS
XFEED SOV
FAIL
OPEN
Engine FeedShutoff ValveCommanded offwhen the fire handleis pulled.
Crossfeed ShutoffValveCrossfeed shutoffvalve is selectedopen by the switch
on the fuel controlpanel.GX
_1
1_
017
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CAUTION
The possibility of engine flameout could occur if thecrossfeed valve is not opened prior to inhibiting the fuelpumps.
In this operating mode, the crossfeed valve is selected open via the XFEED SOV
switch on the fuel control panel. The fuel pumps on the light side of the airplane are
turned off, using the applicable AUX PUMP and PRI PUMP switches. Fuel will then
be supplied from the heavy side of the airplane only, thereby correcting the lateral fuel
imbalance. Crossfeed continues in this mode until the crew deselects the switches after
lateral balance is achieved.
NOTE
It is important that the crew monitor system operation in thismode, since crossfeed will continue until manually deselected.
In the event that a lateral fuel imbalance occurs outside design limits, it will be
annunciated on EICAS, prompting the crew to take action.
The FUEL synoptic page below represents the fuel crossfeed mode (backup) of
operation. The system is shown with the crossfeed shutoff valve selected open, left
auxiliary pump inhibited, left forward and aft boost pumps inhibited, and both engines
running.
FUEL
AUX
3
C
APU
3
C
TOTAL FUELOTAL FUEL
4OOLBS
46OOLBS
AUX
LBS
56OOLBS
FUEL USEDU EL U SE D
96OO
LBS
LO PRESSO P RE SS
3
C
OOLBS
3
C
LO PRESSO P RE SS
L
WINGFEED
INHIBIT
AUXPUMP
OFF
PRIPUMPS
OFF
Crossfeed ShutoffValveCrossfeed shutoffvalve is selectedopen by the switchon the fuel controlpanel.
GX
_11
_018
XFEED SOV
FAIL
OPEN
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AFT TRANSFER
Fuel contained in the aft tank is retained until late in the flight, in order to maintain a
favorable aft center of gravity (C of G).
The aft transfer schedule is normally controlled automatically by the FMQGC. Fuel
can also be transferred or inhibited manually from aft tank to wing tank, using the AFT
XFER switch on the fuel control panel, if desired.
Aft transferring of fuel is achieved using the two AC boost pumps and two shutoff
valves. Each of the two transfer pumps in the system has sufficient capacity to
maintain the transfer schedule in the event of a failure of one of the pumps.
When the aft transfer system is commanded to operate, the aft tank refuel transfer
valve and the aft transfer pump come on. Fuel is then pumped by the aft transfer pump,
into its respective feed tank.
The FUEL synoptic page above represents the fuel aft transfer mode of operation, withboth engines running. The system is shown transferring fuel from the aft tank bladders
to their respective wing tanks.
FUEL
AUX
3
C
APU
3
C
TOTAL FUELOTAL FUEL
9OOOLBS
4OOOLBS
AUX
LBS
4OOOLBS
FUEL USEDU EL U SE D
3 OOO
LBS
LO PRESSO P RE SS
3
C
OOOLBS
3
C
LO PRESSO PR ESS
AFT Transfer PumpIn the AUTO mode, thetransfer schedule iscontrolled by the FMQGC.Manual mode ON or OFFtransfers or inhibits fueltransfer to the wings.
GX
_11
_019
AFTXFER
AUTO
OFF ON
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APU FUEL FEED
The APU start capability is normally provided by the DC AUX pump(s). The fuel
supplied to the APU is taken from the right engine feed line. The APU can also be fed
from the left engine feed line using the left DC AUX pump (powered by DC ESS bus)
and opening the crossfeed shutoff valve (BATT bus). A motor operated fire shutoff
valve is used in the APU feed line, in order to isolate the flow of fuel to the APU in
case of a fire or rotor burst.
The FUEL synoptic page top view represents the APU during the starting sequence,
with the DC pump running and battery power only as the single source of electrical
power. In the lower view, the APU is fed from the right engine feed line using the AC
pumps.
FUEL
AUX
3
C
APU
3
C
TOTAL FUELOTAL FUEL
384OOLBS
46OOLBS
AUX
LBSOO
46OOLBS
FUEL USEDUEL USED
3OOLBS
LO PRESSO P RE SS
3
C
OLBS
3
C
LO PRESSO P RE SS
FUEL
AUX
3
C
APU
3
C
TOTAL FUELOTAL FUEL
384OO
LBS
46OOLBS
AUX
LBSOO
46OOLBS
FUEL USEDUEL USED
3OOLBS
LO PRESSO P RE SS
3
C
OLBS
3
C
LO PRESSO P RE SS
: APU starting andleft and right enginesare off.
Note
:APU on speed andAC electrics established.
Note
TOP VIEW
LOWER VIEW
APU FeedShutoffValve
GX
_11
_020
APU green outlineindicates on-speed.
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FUEL RECIRCULATION SYSTEM
The Fuel ReCirculation system is designed to prevent the bulk fuel temperature from
reaching the freezing point by recirculating heated fuel to the wing fuel tank. The
system is operated through the L and R RECIRC switches on the Fuel Control panel
for aircraft equipped with FMQGC models prior to -9.
On -9 FMQGC models and later, recirculation is an automatic ON function. The
FMQGC will turn on recirc when the altitude is > 34,000 feet, AND the bulk
temperature drops below 20C, or average temperature drops below 9C, and turn
off recirc when the bulk temperature reaches 5C or altitude is < 33,800 feet, or either
engine is turned off. It will turn both sides on or off at the same time.
Heat is generated by the engine oil cooling system. Cold fuel circulated through the
Fuel Cooled Oil Cooler (FCOC) where the heat from the engine oil is transferred tothe fuel. The Fuel Return To Tank (FRTT) valve allows the heated fuel to return to the
wing fuel tank.
When the FRTT valve is open, fuel returns to the wing tank through the recirculation
line. The recirculation line joins the aft tank transfer line. This slightly decreases the
transfer rate of the aft tank to the feed tanks. Heated fuel is then distributed to the
number 1 and 2 cell of the wing fuel tank. No fuel is distributed to the number 3 cell as
it will have emptied before the local fuel temperature reaches 40C (F). Both the
recirculation line and the aft tank transfer line are fitted with a check valve to prevent
crossflow or fuel propagation due to a ruptured line.
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The wing fuel tanks are fitted with many fuel temperature sensors; the left wing hastwo and the right wing has three. With the Fuel Recirculation OFF, the Fuel
Management and Quantity Gauging Computer (FMQGC) reads all temperature
sensors but will display only the lowest temperature. When the Fuel Recirculation
system is ON, the FMQGC computer reads the inboard temperature sensor as it will be
the one who reads the highest temperature.
Operation of the Fuel Recirculation System is allowed only during cruise flight above
34,000 feet.
Display of system status is provided through EICAS messages. A L (R) FUEL
RECIRC FAIL caution message will be displayed on the EICAS status page when the
FRTT valve is not in the commanded or allowed position. The L (R) FUEL RECIRCON status message will be displayed when the system operates properly and within
specification on aircraft equipped with FMQGC prior to -9. Aircraft equipped with
FMQGC -9 or later have a L (R) FUEL RECIRC OFF status message associated with
PBA as the recirc function is automatic.
The FUEL HI TEMP caution message is posted when the bulk fuel temperatureexceeds 43C (FMQGC prior to -9), (+54C -9 FMQGC and later) when the FuelRecirculation System is OFF. To prevent the system from operating above the freezinglevel, the set point has been reduced to 0C (FMQGC prior to -9), (+10C -9 FMQGCand later) when the system is selected on.
P
P
P
P
P
P
TS TS
TS
TS
TS
P P
P P
FCOC FCOC
CELL3
CELL2
CELL1
CENTER TANK
Center Transfer Pump
Wing Transfer Shutoff Valve
Auxilliary DC Pump
Bulk FuelTemperature
Heated Fuel
TemperatureSensorTS
Fuel-Return-to-TankValve
Recirculation Line
Main AC Pumps
AFT TransferShutoff Valve
AFT TANK
AFT Transfer Line
AFT Transfer Pump
Engine FeedShutoff Valve
GX
_11
_021
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REFUEL/DEFUEL SYSTEM
Pressure refueling/defueling operations are controlled from the refuel/defuel control
panel. Pressure refueling can be accomplished in MANUAL or AUTO mode of
operation.
Gravity filling via a filler point is also provided for the wing and center tanks.
PRESEL
INCR
DECR
CLOSE
START
STOP/
SOV
TEST
MANUAL AUTO
OFF
REFUEL
DEFUEL
REFUEL
REFUEL
NOAFT
LEFTCTR
RIGHT
OPEN
AFT
MANUAL
REFUEL/DEFUEL PANEL
TOTAL
PRESEL
LEFT
RIGHT
CENTER
AFT
GRAVITY FILL CAP
GroundingPoints
GroundingPoint
ProximitySensor
PRESEL
INCR
DECR
CLOSE
START
STOP/
SOV
TEST
MANUAL AUTO
OFF
REFUEL
DEFUEL
REFUEL
REFUEL
NOAFT
LEFT CTR RIGHT
OPEN
AFT
MANUAL
REFUEL/DEFUEL PANEL
TOTAL PRESEL
LEFT RIGHTCENTER
AFT
GX
_11
_022
GroundingPoint
REFUEL/DEFUELACCESS PANEL
REFUEL/DEFUEL PANEL
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REFUEL DISTRIBUTION
Refer to Refuel Schematic for component location, recognition, and operation.
All fuel tanks can be refueled either automatically (by the FMQGC) or manually (by
the refuel/defuel panel). The recommended pressure is 50 psig for pressure fueling.
A balance line in each tank is used during refueling to transfer fuel to the most
outboard section of the wing.
The filling sequence of the wing compartment during pressure refueling is as follows:
Cell 2 is filled directly by the refuel system, fuel flows inboard by gravity into
Cell 1, which is the inboard section including the feed tank. After inboard cells 1
and 2 are completely filled
Cell 3 is filled to capacity by overflow of cell 2 fuel through the balance tube
connecting cells 2 and 3
The aft and center tanks will be refueled simultaneously (automatically by the
FMQGC) to maintain center-of-gravity (C of G) limits.
High level sensors installed in each tank automatically close the refuel/defuel SOVs, if
the maximum fuel level capacity is reached. Relief valves augment the normal vent
system to prevent overpressure in case of overfilling a tank.
As with the wing tanks, automatic refueling of the center tank is controlled by the
FMQGC, with automatic shutoff commanded by the high level sensor. Automatic
refueling of the aft tank is controlled by the FMQGC, with automatic shutoffcommanded by the high level sensor.
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REFUEL/DEFUEL SCHEMATIC
FUEL DISTRIBUTION LINESLEFT MAIN REFUEL
RIGHT MAIN FUEL
CENTE REFUEL/DEFUEL
AFT REFUEL/DEFUELAND MAIN DEFUEL
R
CELL
1
CELL
2
CELL
3
REFUELDEFUELPANEL
RV
RV
RV
HH
H HRV
Relief Valve
CrossfeedValve
Shutoff Valve toAFT Tank
Suction DefuelCheck Valve
BalanceTube
Single PointRefuel Adaptor
Baffled Ribs
Defuel ShutoffValve
Center TankRefuel/Defuel CheckValve
Refuel/Defuel
Manifold
Shutoff Valves
TOFMQGC
GX
_11
_023
High LevelSensor
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NORMAL FUEL LOADING
The normal fuel loading logic as planned by the FMQGC is as follows: Note that when
the refuel process starts, fuel flows to all of the tanks at the same time until they reach
the planned amount.
Wing tanks only if the required fuel load is equal to or less than the wing tank
capacity
Wing tanks full and the remainder in the aft tank if the required fuel load is greater
than the wing tank capacity but less than or equal to the combined capacity of the
wing and aft tanks
Any fuel in excess of the combined capacity of the wing and aft tanks is placed in
the center tank
NOTE
The fuel computer always strives to keep between 0 and 400 lbmaximum lateral imbalance, regardless of what FMQGC versionwe have.
For FMQGC (pre-5), the logic was set to stop fuel loading anddisplay inhib on the fuel panel as soon as the lateral imbalancereached 400 lb. Since -5 FMQGC, the software now allows theimbalance to reach 1100 lb before shutting down and going into
inhib mode.
An additional switch position on the refuel/defuel panel allows auto refueling without
adding fuel to the aft tank.
If the aft tank fueling is inhibited by use of this switch, then the refuel sequence is as
follows:
Wing tanks only if the required fuel load is equal to or less than the wing tank
capacity
Wing tanks full and the remainder in the center tank if the required fuel load is
greater than the total wing capacity
Fuel Imbalance Limitations
WING TANK FUEL LOADGROUND/CONFIGURED FOR
TAKEOFF/LANDING
FLIGHT - CLEAN
CONFIGURATION
Less than 19,450 lb 1,100 lb 1,100 lb
19,450 to 20,250 lb 1,100 to 600 lb 1,100 lb
Greater than 20,250 lb 600 lb 1,100 lb
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REFUEL/DEFUEL PANEL
PRESEL
INCR
DECR
CLOSE
START
STOP/
SOV
TEST
MANUAL AUTO
OFF
REFUEL
DEFUEL
REFUEL
REFUELNOAFT
LEFT CTR RIGHT
OPEN
AFT
MANUAL
REFUEL/DEFUEL PANEL
TOTAL PRESEL
LEFT RIGHTCENTER
AFT
MASTER
OFF
ONINCR
DECR
CLOSE
SHUT
OFFSTART
AFTON
AUTO
REFUEL
STARTREFUEL
DEFUEL STOP OFF
LEFT
LEFT RIGHT
CTR AFT
TOTAL PRESEL
CTR RIGHT
OPEN
AFT
MANUAL AUTO REFUEL
REFUEL/DEFUEL PANEL
30000 30000LB LB
10050 9950
8000 2000
MASTER
FUEL QUANTITY DisplaysDisplays current tank quantities.
PRESELECT DisplayIndicates preselected total quantity.
LEFT/CTR/RIGHT/AFTMANUAL SwitchesManually controlsvalves open or closed.
MODE SELECTOR SwitchREFUEL
AUTO REFUEL
DEFUEL
Enables manualrefueling.
Enables autorefueling.
Enable manual defuel.
START/STOP SwitchStarts or stops automaticrefueling.
AFT ON/OFF SwitchEnables/disablesautomatic refueling of theaft tank.
SHUT OFF TEST SwitchPerforms test of theautomatic shutoff system.
MASTER SwitchApplies APU batterypower to refuel/defuelsystem.
INCR/DECR SwitchIncreases or decreases PRESELquantity for AUTO refueling
LEFT/CTR/RIGHT/AFTMANUAL SwitchesManually controlsvalves open or closed.
MODE SELECTOROFFAUTO / REFUEL
AUTO / REFUEL NO AFT
MANUAL / REFUEL
DEFUEL
No power to panelSelected when aircraft to be
fueled automatically to a preselected fuel load.Selected when no fuel
required in aft tank during AUTO refueling.Selected when fuel tanks filled
manually by operator.Selected when defueling
aircraft by manually opening tank SOVs.MANUAL /
PRESEL INCR/DECRSwitchIncreases or decreasesthe preselected quantityfor AUTO refueling
START/STOP/SOV TESTSwitchSTART
STOP/SOV TEST
Starts automaticrefueling
Stopsautomatic refueling andperforms SOV test.
Quantity Displays
EARLIER VERSION
GX
_11
_024
LATER VERSION
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FAULT REPORTING
Fault reporting is in the form of error messages which will appear in the display
windows of the refuel/defuel panel.
The following illustration represents one example of fault reporting:
ERROR MESSAGES
The following messages may be displayed on the refuel/defuel panel if a fault exists:
INHIBIT
In manual refuel or defuel mode, displayed when a tank switch is in the OPEN
position. In pressure defuel mode, displayed when an engine is on (no fire handles
pulled). In auto mode, displayed when the preselected fuel quantity is invalid, airplane
is in CAIMS maintenance mode, or the SOV shutoff test fails.
FULL
Displayed when the high level shutoff has been activated.
LOAD ERRORIn auto refuel mode, displayed when an invalid fuel distribution is selected. Example,
one tank contains more fuel than the target quantity assigned by the automatic
distribution.
IMBAL
Displayed when a predetermined fuel quantity imbalance exists between the left and
right wings.
REPEATER
Displayed in the PRESEL window of the external Refuel/Defuel Panel when two
panels are powered ON. The panel located in the flight compartment is in control and
the outside panel provides quantity display only.
_ _ _ _ _ _
Dashes will be displayed for a fuel quantity if the computed value is invalid.
FAILED
Displayed in the PRESEL window if the Refuel/Defuel Panel is not functional.
FMQGC - FAILURE
FMQGC will be displayed in the TOTAL window and FAILURE in the PRESEL
window if the Refuel/Defuel Panel is not communicating with the fuel computer.
TOTAL PRESEL
LEFT RIGHTCENTER
AFT
REPEATERThis indicates that twopanels are powered on.
GX
_11
_025
10000 8000
30000 2000
10000
REPEATER
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PRESSURE REFUELING
Pressure refueling is accomplished through the single point refuel/defuel adapter,
located in the right hand wing root, and is controlled by the refuel/defuel control panel.
An optional duplicate refuel/defuel control panel can be installed in the flight
compartment.
NOTE
A SHUTOFF TEST must be carried out prior to all refuelingoperations.
If the test is successful, a SOV PASS is displayed in the PRESEL window. If the test
fails, a SOV FAIL is displayed in the PRESEL window.Pressure refueling may be performed in either automatic or manual mode. The
airplane does not have a fuel jettison system.
A preselect fuel quantity is used during automatic refueling of the airplane. This
method will allow the airplane to be filled automatically to the desired fuel state
selected.
NOTE
The preselect quantity is the desired final total fuel quantity in thetanks, and not the quantity to be added.
The computer determines the required distribution of fuel into each of the aircraft
tanks to achieve the preselected value and controls each refuel valve accordingly. The
refuel schedule (planning only) will fill the wings first, then the aft tank, then the
center tank. If the aft or center tanks are used each will be fueled to a minimum of 500
pounds to ensure pump priming. The shutoff point, for each tank, is anticipated by
the computer by monitoring the refueling rate to determine the correct shutoff point for
each individual refueling operation.
When auto refueling is terminated by the computer, the quantity showing in the
TOTAL window is equal to that in the PRESEL window.
Auto refueling can be interrupted at any time by moving the START/STOP switch tothe STOP position. Individual tank quantities can be seen in the other two windows of
the display.
The AFT ON/OFF switch allows auto refueling to take place with or without fuel
being placed in the aft tank.
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EARLIER VERSION RDCP REFUEL/DEFUEL PROCEDURES
NOTES
1. The maximum refueling pressure is 50 psig.2. The Tank Pressure Relief Valves must be tested for properfunction prior to refueling by manually operating the threeexternal pull handles.3. Maximum fuel imbalance of 400 pounds/1100 pounds(depending on FMQGC software version, see NORMAL FUELLOADING section) is allowed between the two main tanks,following which, the tank quantity window on the RDCP flashesan IMBAL message alternating with the tank quantities every twoseconds.4. A SHUTOFF TEST of the system must be conducted duringeach refueling.
AUTO REFUEL
The procedure for auto refuel is as follows:
Open the RDCP access panel
Place the MASTER switch in the ON position
Allow the FMQGC to conduct BITE test until tank quantities are displayed steady
in all windows
NOTE
If a system fault is detected, the windows will display dashedlines or error message(s) in the individual tank windows insteadof quantities. Do not proceed without investigating and rectifyingfault.
Verify no error messages are displayed in any of the individual tank quantity
windows
Verify all MANUAL tank switches are in the CLOSE position
Place the MODE SELECTOR switch in the AUTO REFUEL position
Note the quantities in the TOTAL and PRESEL windows. They should be the
same
Place the AFT switch in the ON or OFF position as required
Hold the PRESEL switch in the INCR position until the PRESEL window displays
the desired total fuel quantity
Connect the refuel tender to the single point adapter and adjust the tender pressure
as desired but not to exceed 50 psig
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Place the START/STOP switch in the START position and release it
Verify tank quantities show increase
Place the spring-loaded SHUTOFF TEST switch in the TEST position and hold it.
Verify the PRESEL window displays SOV TEST
Verify all tank quantities stop increasing to confirm the refuel valves have closed
Verify the PRESEL window displays SOV STOP alternating with the preselected
value and does not display SOV FAIL
Release the SHUTOFF TEST switch and verify tank quantities resume showing
increase with the preselected quantity showing steady in the PRESEL window
The FMQGC shall control the fueling sequence automatically within the required
loading sequence
When all tank quantities stop registering an increase, verify that the displays in the
TOTAL and the PRESEL window are the same and no error message is displayed
in any of the windows. Each tank window should display the quantity in it as
distributed by the FMQGC in the automatic mode and should add up to the
TOTAL displayed
Disconnect the tender as required and return the RDCP MASTER switch to the
OFF position
Secure RDCP access panel
MANUAL REFUELING
In manual mode, it permits the operator to select and control the fuel quantity to be
added in each tank through the refuel/defuel panel. In this mode, the high level sensors
automatically close the refuel/defuel SOVs, if the maximum fuel level capacity is
reached.
MANUAL REFUEL
The procedure for manual refuel is as follows:
Open the RDCP access panel
Place the MASTER switch in the ON position
Allow the FMQGC to conduct BITE test until tank quantities are displayed steadyin all windows
NOTE
If a system fault is detected, the windows will display dashedlines or error message(s) in the individual tank windows insteadof quantities. Do not proceed without investigating and rectifyingfault.
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Verify no error messages are displayed in any of the individual tank quantity
windows Verify all MANUAL tank switches are in the CLOSE position
Verify MODE SELECTOR switch is in the mid position marked AUTO REFUEL
Note the quantities in the TOTAL and PRESEL windows. They should be the
same
Move the MODE SELECTOR switch up to the position marked MANUAL
REFUEL
Verify the PRESEL window displays the message MANUAL instead of quantity
Connect the refuel tender to the single point adapter and adjust the tender pressure
as desired but not to exceed 50 psig
Select the desired tank MANUAL switches to the OPEN position
Verify that the selected tank quantities show increase
Place the spring loaded SHUTOFF TEST switch in the TEST position and hold it
Verify the PRESEL window displays SOV TEST
Verify all tank quantities stop increasing to confirm the refuel valves have closed
Verify the PRESEL window displays SOV STOP alternating with MANUAL and
does not display SOV FAIL
Release the SHUTOFF TEST switch and verify tank quantities resume showing
increase with MANUAL showing steady in the PRESEL window
When the desired fuel quantity for the selected tank is displayed on the tankwindow, return the MANUAL switch to the CLOSE position to terminate the
fueling operation
Return the MODE SELECTOR switch to AUTO REFUEL
Disconnect the tender as required and return the RDCP MASTER switch to the
OFF position
Secure RDCP access panel
GRAVITY REFUELING
The wing tanks may be refueled through over wing gravity fill adapters located on top
of both left and right wings. It is not possible to completely fill either wing tank bygravity fueling, since the fill adapters are located outboard and below the maximum
fuel level.
The center tank may be refueled through a gravity fill adapter located on top of the
right hand wing.
Gravity fueling of the aft tank is not possible therefore; no fill adapter is provided.
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SUCTION DEFUELING
Suction defueling of the fuel tanks is carried out by applying suction (recommended
pressure of -8 psig) to the single point refuel/defuel adapter, using the refuel/defuel
control panel.
WING TANK
Suction defueling of the wing tanks is accomplished by opening a valve which
connects the refuel/defuel manifold to the engine feed line. This allows fuel to be
drawn out of the tank through the suction defuel check valve in the feed tank.
CENTER TANK
The center tank is defueled through the refuel/defuel shutoff valve.
AFT TANK
The aft tank may be suction defueled, using the same line and shutoff valve used for
pressure refueling of the tank.
SUCTION DEFUEL
The procedure for suction defuel is as follows:
Open the RDCP access panel
Place the MASTER switch in the ON position
Allow the FMQGC to conduct BITE test until tank quantities are displayed steady
in all windows
NOTE
If a system fault is detected, the windows will display dashedlines or error message(s) in the individual tank windows insteadof quantities. Do not proceed without investigating and rectifyingfault.
Verify no error messages are displayed in any of the individual tank quantity
windows Verify all MANUAL tank switches are in the CLOSE position
Verify the AUTO REFUEL switch is in the mid position marked AUTO REFUEL
Note the quantities in the TOTAL and PRESEL windows. They should be the
same
Move the MODE SELECTOR switch to the position marked MANUAL DEFUEL
Verify the PRESEL window displays the message DEFUEL
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Connect the refuel tender to the single point adapter and adjust the tender pressure
to negative 8 psig (suction) maximum Select the desired tank MANUAL switches to the OPEN position
Verify tank quantities show decrease
When the desired fuel quantity for the selected tank is displayed on the tank
window, return the MANUAL switch to the CLOSE position to terminate the
defueling operation
Move the MODE SELECTOR switch to AUTO REFUEL
Disconnect the tender as required and return the RDCP MASTER switch to the
OFF position
Secure RDCP access panel
PRESSURE DEFUELING
Pressure defueling of the fuel tanks is accomplished through the fuel shutoff valves
and single point adapter. Pressure defueling is identical to suction defueling, except
that primary defueling flow is provided by the AC boost pumps or DC auxiliary pump
in each feed tank.
NOTE
AC or DC electrical power is required to operate the airplanepumps for this procedure.
Direct pressure defueling of the wing tank is accomplished using the AC boost pumps
or DC auxiliary pump in each feed tank.
Direct pressure defueling of the center tank is not possible. Center tank fuel may
however be transferred to the wing tanks using the center tank transfer pumps. From
there, it may then be defueled via the wing tank.
Direct pressure defueling of the aft fuselage tank is not possible. Aft fuselage tank fuel
may however be transferred to the wing tanks using the aft transfer pumps. From the
wing tank, it may then be defueled via the wing tank.
LATER VERSION RDCP REFUEL/DEFUEL PROCEDURESDifferences in Later Refuel/Defuel Panel are as follows:
The MODE SELECTOR switch is now rotary and includes the aft tank control
switch
The START/STOP switch now includes the SOV test function
The master ON/OFF switch is part of the mode selector switch
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EICAS MESSAGES
GX
_11
_026
AFT XFER OFF SCHEDFUEL COMPUTR FAIL
FUEL LO QTYL (R) FUEL RECIRC FAIL
L (R) PRI FUEL PUMPSWING TO CTR LEAK
FUEL IMBALANCE
FUEL UNIT MISMATCHFUEL XFER FAILFUEL XFER ONFUEL XFER FAILFUEL XFER ON
FUEL TEMP SENSOR
FUEL UNIT MISMATCHThe refuel/defuel panel andEICAS indications are correctbut in different units ofmeasurements.
AFT XFER OFF SCHEDIndicates that fuel transfer fromthe aft tanks to the wings is
unable to keep pace with theoptimum aft transfer schedule.
FUEL XFER ONIndicates that fuel is beingtransferred from the left wing
tank to the right wingunrequested.
FUEL XFER ONIndicates that fuel is beingtransferred from the right wingtank to the left wingunrequested.
FUEL COMPUTR FAILIndicates that both channels ofthe fuel system computer havefailed.
L (R) PRI FUEL PUMPSIndicates both left or both rightforward and aft primary ACpumps have failed to operatewhen requested.
WING TO CTR LEAKIndicates that the fuel level inthe center tank has increased by600 lbs or more.
FUEL XFER FAILTransfer from the left wing to theright wing has been requestedand failed.
FUEL XFER FAIL
Transfer from right wing to leftwing has been requested andfailed.
FUEL TEMP SENSOROn ground, indicates that a fueltemperature sensor is failed.With flaps deployed, will beposted only if the failure requirescorrective action.
FUEL IMBALANCEIndicates that a fuel quantity imbalanceexists between the left and right wingtanks of: More than 1100 lbs (499 kg) in flight
Between 600 lbs (272 kg) and 1100lbs (499 kg) on ground or in Takeoff /Approach configuration.
FUEL LO QTYIndicates fuel in the left or rightwing tank is less than 600 lbs(272 kg).L (R) FUEL RECIRC FAIL
Indicates that the FRTT valve isnot in the commanded orallowed position.
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EICAS MESSAGES (Cont)
AFT XFER FAILAPU FUEL SOVL (R) ENG FUEL SOVCTR FUEL XFER FAILWING FUEL HI TEMPWING FUEL LO TEMPL (R) WING FULLL (R) PRI FUEL PUMPL (R) AUX FUEL PUMP
CTR XFER FAULTXFER VALVE OPENFUEL XFER ON
XFEED VALVE FAIL
APU FUEL SOV
Indicates that the APU fuelshutoff valve has failed.
GX
_11
_027
L (R) WING FULLIndicates that fuel quantity inthe left or right wing tank hasexceeded its maximumallowable value.
L (R) AUX FUEL PUMPIndicates that the auxiliary fuelpump on the affected side hasfailed to operate whenrequested.
WING FUEL HI TEMPIndicates that the left or rightwing fuel bulk temperature isabove the high temperaturelimit.
L (R) ENG FUEL SOVIndicates that the engine fuelshutoff valve on the affectedside is not in its commandedstate.
XFER VALVE OPENIndicates that the wing transfervalve has failed to close at thecompletion of wing transferoperation.
CTR FUEL XFER FAILIndicates that both left and rightcenter tank pumps have failedto operate when requested.
WING FUEL LO TEMPIndicates that either the left orright wing fuel bulk temperatureis below -35C.
L (R) PRI FUEL PUMPIndicates that a single primaryfuel pump on the affected sidehas failed to operate whenrequested.
CTR XFER FAULTIndicates a center fuel transferfault exists (either the left orright fuel transfer is notworking).
FUEL XFER ONIndicates that the left to righttransfer system is in the AUTOmode of operation.
XFEED VALVE FAILIndicates that the crossfeed valveis not in its commanded position.
AFT XFER FAILBoth left and right aft transfercomponents have failed to operatewhen requested. Aft tank fuel is nolonger available.
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EICAS MESSAGES (Cont)
FUEL XFER ONXFER VALVE OPEN
AFT XFER FAULTAFT XFER OFF SCHEDFUEL COMPUTR FAULTFUEL QTY DEGRADEDFUEL RECIRC ONL (R) R/D VALVE OPEN
AFT R/D VALVE OPEN
AFT XFER OFF SCHEDIndicates aft tank fueltransfer to the wings, inadvance of the optimumtransfer schedule.
AFT XFER FAULTIndicates that either a leftor right aft tank fueltransfer component hasfailed to operate whenrequested.
FUEL COMPUTR FAULTIndicates that either channelof the computer has failed.
FUEL QTY DEGRADEDIndicates that the fuelcomputer detects a loss offuel gauging accuracy.
FUEL RECIRC ONOn aircraft with FMQGCpre-9 the fuel recirculationsystem is operating in anon-allowed configuration
L (R) R/D VALVE OPENThe left or right defuel valvehas failed to close (afterdefuel operation) whenrequested.
XFER VALVE OPENIndicates that the wingtransfer valve has failed toclose at the completion ofwing transfer operation.
FUEL XFER ONIndicates that the right to left
transfer system is in theAUTO mode of operation.
G
X_
11
_028
AFT R/D VALVE OPENThe aft refuel/defuel valvehas failed to close afterrefuel/defuel operation)when requested.
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EICAS MESSAGES (Cont)
L (R) PRI PUMPS OFFL (R) AUX PUMP OFF
FUEL XFER ONFUEL XFER ON
AFT FUEL XFER OFFAFT FUEL XFER ONWING FUEL XFER OFFXFEED VALVE OPENL (R) ENG SOV CLSD
APU FUEL SOV CLSDFUEL RECIRC ONFUEL RECIRC OFF
L (R) PRI PUMPS OFF
Indicates that the left or rightforward and aft boost pumpsare inhibited.
GX
_11
_029
FUEL XFER ONIndicates that the left to righttransfer system is in the MANUALmode of operation.
AFT FUEL XFER OFFIndicates aft fuel transfer has beeninhibited.
WING FUEL XFER OFFIndicates that transfer of fuel fromleft to right, and from right to lefthas been selected off.
L (R) ENG SOV CLSDIndicates that left or right fuelshutoff valve is closed.
L (R) AUX PUMP OFFIndicates that the left or rightauxiliary pump has beeninhibited.
FUEL XFER ONIndicates that the right to lefttransfer system is in theMANUAL mode of operation.
AFT FUEL XFER ONIndicates aft fuel transfer is inprogress under manual control.
XFEED VALVE OPENIndicates that the crossfeedshutoff valve is open.
APU FUEL SOV CLSDIndicates that APU fuel shutoffvalve is closed.
FUEL RECIRC ONIndicates that the FRTT valves areopened when commanded by flightcrew. Prior to -9 FMQGC..
FUEL RECIRC OFFIndicates that the FRTT valvesare closed when commandedby flight crew. -9 FMQGC andlater.
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EMS CIRCUIT PROTECTION
BRT
CIRCUIT BREAKER SYSTEM
STAT SYS BUS PREV
PAGE
NEXT
PAGE CNTL TE ST
BUS
EMER
CONT
CB - FUEL SYSTEM 1/6
XFER SOV C
XFER SOV O
XFER SOV C
XFER SOV O
AFT TANK L PUMP
AFT TANK L SOV C
DC ESS
DC ESS
BATT
BATT
AC 2
DC 1
IN
IN
IN
IN
IN
IN
2/6
AFT TANK L SOV O
AFT TANK R PUMP
AFT TANK R SOV C
AFT TANK R SOV O
APU FIRE SOV
FUEL COMPUTR CH A
DC 1
AC 3
DC 2
DC 2
DC EMER
BATT
IN
IN
IN
IN
IN
IN
X
X
X
X
DCPC
R AFT PRI PUMP
R AUX PUMP
R CTR XFER PUMP
L ENG FUEL SOV
L FWD PRI PUMP
L FUEL RECIRC VLV
AC 4
BATT
AC 4
DC EMER
AC 2
DC 1
CB - FUEL SYSTEM
CB - FUEL SYSTEM 4/6
X
X
X
DCPC
X
X
IN
IN
IN
IN
IN
IN
5/6
R ENG FUELSOV
R/D MOTOR VALVES
R/D PANEL COCKPIT
R/D PANEL EXT
R FWD PRI PUMP
R FUEL RECIRC VLV
DC EMER
APU BATT
APU BATT
APU BATT
AC 3
DC 2
CB - FUEL SYSTEM
IN
IN
IN
IN
IN
IN
NOTE: The fuel recirculation protection is not active, TBD by flight test.
FUEL COMPUTR CH B
FUEL R/D CH A
FUEL R/D CH B
L AFT PRI PUMP
L AUX PUMP
L CTR XFER PUMP
DC ESS
APU BATT
APU BATT
AC 1
DC ESS
AC 1
6/6
R/D SOL VALVES
X FEED SOV C
XFEED SOV O
APU BATT
BATT
BATT
ASCAX
ASCA
ASCA
IN
IN
IN
CB - FUEL SYSTEM CB - FUEL SYSTEM3/6
IN
IN
IN
IN
IN
IN
GX
_11
_030
M
CIRCUIT BREAKER - SYSTEM 1/2
AFCS
AIR COND/PRESS
APU
BLEED
CAIMS
COMM
DOORS
ELEC
ENGINE
FIRE
FLT CONTROLS
FUEL
DCPC
X
X
ASCA
ASCA
ASCA
Bombardier Global Express - Fuel System
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